/*
 *  Copyright (c) 2019, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 *  WSO2 Inc. licenses this file to you under the Apache License,
 *  Version 2.0 (the "License"); you may not use this file except
 *  in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.wso2.carbon.apimgt.gateway.jwt;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.Iterator;
import java.util.Map;
import java.util.Timer;
import java.util.TimerTask;

/**
 *  Responsible to remove expired revoked JWTs from the revoke map
 */
public class RevokedJWTMapCleaner extends TimerTask {

    private static final Log log = LogFactory.getLog(RevokedJWTMapCleaner.class);

    @Override
    public void run() {

        log.debug("Starting revoked JWT map cleaner task.");
        cleanJWTRevokedMap();
    }

    private void cleanJWTRevokedMap() {

        long currentTimestamp = System.currentTimeMillis();
        Map<String, Long> revokedMap = RevokedJWTDataHolder.getInstance().getRevokedJWTMap();
        Iterator it = revokedMap.entrySet().iterator();
        int count = 0;
        while (it.hasNext()) {
            Map.Entry entry = (Map.Entry) it.next();
            long expiryTime = (long) (entry.getValue()) * 1000;
            if (currentTimestamp > expiryTime) { // if token is expired, remove from the revoked map
                it.remove();
                if (log.isDebugEnabled()) {
                    log.debug("Removed entry : " + entry.getKey());
                }
                count++;
            }
        }
        if (log.isDebugEnabled()) {
            log.debug("Number of removed JWT tokens from the map : " + count);
        }
    }

    /**
     * Starts the timer task to clean the JWT revoke map
     */
    public void startJWTRevokedMapCleaner() {
        // Thread starts after 2 mins and runs every 45 minutes
        new Timer().schedule(this, 120000, 2700000);
    }
}
